Re: UNID 20.04./20:31 UTC

Ralph McConahy (
Wed, 21 Apr 1999 21:45:45 -0700

Hej då, Marco at wrote:

>Yesterday evening I observed two satellites flying almost in parallel and
>disappearing into shadow around 20:31 UTC (+/- 1 minute) near altitude 80
>degrees, azimut 45 degrees. My location was 54.456N, 9.622E. The two
>were separated by about 10 degrees alongtrack, the tracks by about 3
>They moved from south to north (i. e. right to left as seen by me), maybe a
>slight change in altitude was occurring over the 30-40 degree part of the
>that I saw. The upper satellite was about 4th magnitude, the lower one
>2nd magnitude.
>One possible match according to the new_elem from April 15th could be:
>ERS 2
>1 23560U 95021  A 99104.20866280  .00000226  00000-0  10000-3 0  6977
>2 23560  98.5489 179.4510 0000936  67.8084 292.3205 14.32247536208155
>however, it is about 2 minutes late and comes out of the shadow instead of
>disappearing into it. The track fits, though.

By "yesterday" I assumed the date was Apr 20 UT.

You wrote that it was near 80 deg elevation, but that it didn't change much
in elev for at least 30-40 deg [in azimuth]. A trajectory that takes it
through 80 deg El spends most of its time changing in elevation. Looking at
your example of the track of ERS 2 seems to show (again, assuming Apr 20 as
the date) that perhaps the angles were 80 Az and 45 El instead of 45 Az 80
El. Given this, perhaps you did see ERS 2 with its companion being Resurs
1-4 r (98-43G, 25400). These two fit the relation to one another that you
described except that the brighter of the two (Resurs 1-4) would have been
above ERS 2, instead of the brighter one being the lower one as you noted.

   Ralph McConahy
   34.8829N  117.0064W  670m